Month: January 2018

Let me start with some bad news first: I have a cold, or flu, or whatever that is that’s been bugging me for a week now. And not just me I’m afraid – so long story short the Saturn ODEs will have to wait until 2nd or 3rd week of February. Hopefully by then I will have enough of either Rheas or Phoebes to take orders.

Since I’m having some trouble with PCE I decided to do something else, for the fun of it. I got some help too so a lot of time consuming tasks (like checking what signals go to what chips) were done for me. Again long story short I’ve recently made this:

It’s FM Towns Marty ODE I’m calling DocBrown – and the good news is I just got it to boot games this past weekend. Now, obviously it’s a prototype but seems to work pretty well actually, even if right now it needs that FPGA next to it to fix timings on one of the signals that I can’t get right with the MCU alone. I should be able to overcome this with some external logic/PLD though, I already have an idea and if parts arrive soon I can test it next weekend.

So far I’ve tested: Flashback, Loom, Indiana Jones and the Fate of Atlantis and Ultima Underworld – everything works. UU loading time is still terrible but that’s how the game was coded, it does a lot of short reads (tons of small files) and Marty requires drive seek times not to be zero. Still way faster than original drive, plus I found out I might be able to offer a small data transfer speedup via signal overclocking. It’s going to be optional and not enabled by default, and it’s just 10% or so – nothing fancy. Oh and the hardware was designed with CD+G support in mind but I haven’t tested or even coded that yet, first I need to get that core functionality right.

Anyway, if Marty ODE is something you’re interested in buying please leave a short comment – when/if I get it working without FPGA I could order revised PCBs for initial batch. Do note Marty drive is not the same as in regular FM Towns! If it’s the other one you want please leave a comment too, I might just buy that system next 🙂

I’m old enough to remember that a 386 not respecting R/W page bits in ring 0 was a big deal that had to be worked around in SW, incurring performance penalty. Fast forward a couple of decades and it seems paging is still a difficult subject. Make no mistake, this is no bug (Intel admits as much) but a design decision that produced perhaps faster but ultimately unsecure CPUs. Welp, not my problem, I have a buggy Ryzen 🙂

Anyway, I have some GDEMUs for sale so I will be taking orders this Saturday. Not all that many so it’ll probably be a short sale. More devices are in production and I should have some more Saturn ODEs soon as well. As in maybe this month but I’m not sure about that yet.

Very sorry about lack of PCE status updates, my December was more busy than I predicted, but there will be something worth showing in the coming weeks. Turns out working on so many projects at once can slow things down quite a lot. Who knew?

EDIT: GDEMU orders are open closed. Before you complain about this being sneaky, trust me, it’s the better solution. A lot of you claim you’d be willing to get on the list even if it meant months of waiting, so long you were sure you are getting one. Let’s just say I tried that and know from experience it’s BS so I won’t be doing it this way anymore.